Before investigations may begin, the jurisdiction of the Court with respect to a ‘situation’ must be triggered in one of three ways: a resolution of the United Nations Security Council, referral by a State Party and decision of the Pre-Trial Chamber authorizing the Prosecutor to proceed proprio motu. When the Security Council or a State Party refers a situation, the Prosecutor conducts a preliminary examination before deciding to proceed with an investigation. Should the Prosecutor decline to investigate, the Security Council or the State Party may apply for judicial review of the decision by the Pre-Trial Chamber. Special rules apply for triggering of jurisdiction over the crime of genocide by a State Party or by the Prosecutor. Pursuant to Article 16, the Security Council may temporarily block prosecution of a situation.

The Prosecutor begins by identifying situations for ‘preliminary examination’. A list of countries being considered for publication is published on the website of the Court. The Prosecutor reports annually to the Assembly of States Parties on the situations being considered at the preliminary examination stage. After deciding to proceed with an investigation, the Prosecutor applies for warrants of arrest or summonses to appear. When the accused appears before the Court, it may decide to allow interim release although detention during the proceedings appears to be the general rule. The case will not proceed for trial in the absence of the accused. The Pre-Trial Chamber must confirm the charges, following a hearing. The Pre-Trial Chamber also oversees the preparation of the case for trial, including disclosure of prosecution evidence to the defence.